| Message ID | 20240820170150.377580-2-andrew.jones@linux.dev (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [kvm-unit-tests] riscv: Make NR_CPUS configurable | expand |
On Tue, Aug 20, 2024 at 07:01:51PM GMT, Andrew Jones wrote: > Unit tests would like to go nuts with the number of harts in order > to help shake out issues with hart number assumptions. Rather than > set a huge number that will only be used when a platform supports > a huge number or when QEMU is told to exceed the recommended > number of vcpus, make the number configurable. However, we do bump > the default from 16 to 2*xlen since we would like to always force > kvm-unit-tests to use cpumasks with more than one word in order to > ensure that code stays maintained. > > Signed-off-by: Andrew Jones <andrew.jones@linux.dev> > --- > configure | 8 ++++++++ > lib/riscv/asm/setup.h | 3 ++- > 2 files changed, 10 insertions(+), 1 deletion(-) > > diff --git a/configure b/configure > index 27ae9cc89657..6a8d6239a3cb 100755 > --- a/configure > +++ b/configure > @@ -77,6 +77,8 @@ usage() { > Specify the page size (translation granule). PAGE_SIZE can be > 4k [default], 16k, 64k for arm64. > 4k [default], 64k for ppc64. > + --max-cpus=MAX_CPUS > + Specify the maximum number of CPUs supported. (riscv64 only) > --earlycon=EARLYCON > Specify the UART name, type and address (optional, arm and > arm64 only). The specified address will overwrite the UART > @@ -168,6 +170,9 @@ while [[ "$1" = -* ]]; do > --page-size) > page_size="$arg" > ;; > + --max-cpus) > + max_cpus="$arg" > + ;; > --earlycon) > earlycon="$arg" > ;; > @@ -496,8 +501,11 @@ cat <<EOF >> lib/config.h > > EOF > elif [ "$arch" = "riscv32" ] || [ "$arch" = "riscv64" ]; then > + [ -z $max_cpus ] && max_cpus='(__riscv_xlen * 2)' > + > cat <<EOF >> lib/config.h > > +#define CONFIG_NR_CPUS $max_cpus > #define CONFIG_UART_EARLY_BASE 0x10000000 > > EOF > diff --git a/lib/riscv/asm/setup.h b/lib/riscv/asm/setup.h > index a13159bfe395..43b63c56d96f 100644 > --- a/lib/riscv/asm/setup.h > +++ b/lib/riscv/asm/setup.h > @@ -2,9 +2,10 @@ > #ifndef _ASMRISCV_SETUP_H_ > #define _ASMRISCV_SETUP_H_ > #include <libcflat.h> > +#include <config.h> > #include <asm/processor.h> > > -#define NR_CPUS 16 > +#define NR_CPUS CONFIG_NR_CPUS > extern struct thread_info cpus[NR_CPUS]; > extern int nr_cpus; > extern uint64_t timebase_frequency; > -- > 2.45.2 > I started having second thoughts about this approach since we'll have to keep adding configure command line options for every CONFIG option. I posted an alternative approach now [1] and CC'ed everyone since other architectures should chime in on the approach too. [1] https://lore.kernel.org/all/20240903143946.834864-4-andrew.jones@linux.dev/ Thanks, drew
diff --git a/configure b/configure index 27ae9cc89657..6a8d6239a3cb 100755 --- a/configure +++ b/configure @@ -77,6 +77,8 @@ usage() { Specify the page size (translation granule). PAGE_SIZE can be 4k [default], 16k, 64k for arm64. 4k [default], 64k for ppc64. + --max-cpus=MAX_CPUS + Specify the maximum number of CPUs supported. (riscv64 only) --earlycon=EARLYCON Specify the UART name, type and address (optional, arm and arm64 only). The specified address will overwrite the UART @@ -168,6 +170,9 @@ while [[ "$1" = -* ]]; do --page-size) page_size="$arg" ;; + --max-cpus) + max_cpus="$arg" + ;; --earlycon) earlycon="$arg" ;; @@ -496,8 +501,11 @@ cat <<EOF >> lib/config.h EOF elif [ "$arch" = "riscv32" ] || [ "$arch" = "riscv64" ]; then + [ -z $max_cpus ] && max_cpus='(__riscv_xlen * 2)' + cat <<EOF >> lib/config.h +#define CONFIG_NR_CPUS $max_cpus #define CONFIG_UART_EARLY_BASE 0x10000000 EOF diff --git a/lib/riscv/asm/setup.h b/lib/riscv/asm/setup.h index a13159bfe395..43b63c56d96f 100644 --- a/lib/riscv/asm/setup.h +++ b/lib/riscv/asm/setup.h @@ -2,9 +2,10 @@ #ifndef _ASMRISCV_SETUP_H_ #define _ASMRISCV_SETUP_H_ #include <libcflat.h> +#include <config.h> #include <asm/processor.h> -#define NR_CPUS 16 +#define NR_CPUS CONFIG_NR_CPUS extern struct thread_info cpus[NR_CPUS]; extern int nr_cpus; extern uint64_t timebase_frequency;
Unit tests would like to go nuts with the number of harts in order to help shake out issues with hart number assumptions. Rather than set a huge number that will only be used when a platform supports a huge number or when QEMU is told to exceed the recommended number of vcpus, make the number configurable. However, we do bump the default from 16 to 2*xlen since we would like to always force kvm-unit-tests to use cpumasks with more than one word in order to ensure that code stays maintained. Signed-off-by: Andrew Jones <andrew.jones@linux.dev> --- configure | 8 ++++++++ lib/riscv/asm/setup.h | 3 ++- 2 files changed, 10 insertions(+), 1 deletion(-)